Computing devices, such as notebook computers, personal data assistants (“PDAs”), and mobile handsets, have user interface devices, which are also known as human interface devices (“HID”). One type of user interface device that has become more common is a capacitive sense interface. This technology is often referred to as capacitive touch-sense technology; however, this term is a misguided term since the user need not actually physically touch the interface to operate the technology. Rather, the user need only bring a conductive object (e.g., a finger) in close proximity to the capacitive sense interface.
Capacitive sense interfaces may assume a variety of shapes and sizes. FIG. 1 illustrates a conventional circular slider interface 105 having a center mechanical button 110. The illustrated circular slider interface 105 includes eight radial capacitive sensors 115 encircling a mechanical button 110 and an attached processing device 120. The radial capacitive sensors 115 are grouped in an annulus shape about mechanical button 110. Radial capacitive sensors 115 are electrically isolated and spatially distinct from mechanical button 110. Processing device 120 monitors capacitive changes in each of radial capacitive sensors 115 to register user interactions with circular slider interface 105. Processing device 120 may also monitor mechanical button 110 to register a mechanical actuation.
Circular sliders may be used to convey absolute positional information of a conductive object, such as to emulate a mouse in controlling cursor positioning on a display or to emulate a scrolling function of a mouse. Circular sliders may also be used to actuate one or more functions associated with various sensing elements of the circular slider.